Death has become an acceptable and even a fashionable topic. Conversations about death are becoming speculations about the amenities of bland final visits to Holland or Switzerland. Very soon, as entrepreneurs recognize and grasp the rich opportunities, such cosy suburban deaths will be only the economy-end of a spectrum of choices stretching to deluxe departures, precisely timed at sunrise or sunset in mountain, woodland or tropical beach locations with optional champagne, vintage brandy, succulent canapes, background music of choice, professional recording of last words and terminal selfies. We are becoming Cool about Death, but are not yet de-sensitized to a much more disturbing issue: Before we can splash out our savings on a Premium Last Passage we may become demented and a pitiful burden to ourselves and any who care for us. What are the odds of such disasters and can we do anything to tilt them in our favour ?

All studies agree that our chances of our escaping dementia are much better than we might fear. The most common dementia is Alzheimer’s disease (AD) a neurodegenerative condition with brain changes including characteristic patterns of progressive nerve-cell deaths associated with changes in protein metabolism and, on microscopic examination of the brain marked by scar-like plaques and “neurofibrilliary tangles”. These first appear in the neocortex and eventually spread to the hippocampus. Another neurodegenerative condition, Pick’s Disease, or Lewy Body Dementia is, happily, much less common. After neurodegenerative conditions the most common dementias are associated with problems with brain blood supply, such as ruptures and blockages of tiny blood vessels causing deaths of small areas of brain tissue that they serve. Like the risk of AD the risk of such Vascular Dementias increases with age. A very large 1994 Canadian Study of Health and Aging [ 1 ] found that overall incidence of all kinds of dementias was 23% for those aged 85 to 89 and increased to 40% in a 90-94 year old group and 58% in a relatively small group who were over 95. Over all age-groups AD accounted for 75% and vascular dementia for 13% of all dementias. Incidence of AD cases increased faster than of Vascular Dementia cases after 65 and was higher in the 85+ group than in those aged 65 to 85. It is useful to remember that these numbers refer to survivors in each age group. This means that most people in this, and all other populations die without experiencing dementias. The amount and quality of comfort you get from this thought will depend, of course, on your personal views on life and death. I find it rather cheering.

What factors increase risk of these obnoxious conditions and what can we do to improve our chances of avoiding them? Analyses comparing results of many studies suggest that the Canadian figures are quite typical because the risks of dementias do not much differ between countries [2]. As these show, the risk of dementias markedly increases with age. Some analyses combining data from several studies suggest that this accelerated increase in risk with age slows down in the late 80’s and 90’s but other surveys find a linear increase continuing after 85. Diagnoses are sometimes uncertain because brains of older people who experience only very mild mental declines, often called “Mild Cognitive Impairment” often show AD-like changes in nerve cells. On the other hand Mild Cogntive Impairment is a strong risk factor for future AD and other dementias. A different neurodegenerative dementia, Pick’s Disease, or “Lewy Body Dementia” is relatively rare, and so less well documented, but is also age-related. Probably a more common neurodegenerative dementia than Picks associated with Parkinson’s disease, in which it is certainly not an inevitable outcome but affects about 40% of sufferers [3].

As these numbers suggest the strongest risk factor for all dementias is getting old. The reason for the increased incidence of dementias, melodramatically described by the media as an “epidemic” or “plague”, is not that they are contagious or are becoming more common at any particular age but just that more of us now survive to experience them. A crucial comfort is that in this context “Age” is not the remorseless tally of our birthdays, “Calendar Age”, but “Biological Age” the amount and rate at which our bodies and brains have changed and how fit we still remain. The check-list of risks is almost identical for both Alzheimer’s and Vascular Dementias because most factors that impair well-being increase risk of both. One exception is that a genetic factor, apolipoprotein e4-allele seems to increase risk of AD and, in particular, increases the risk from all other unhelpful lifestyle factors. Smoking is very bad news, as is being fat, especially if we have put on weight during or before middle age and not slimmed down since. Nevertheless even elderly long-term fatties should never surrender the struggle to lose weight because this still significantly reduces risks. Diabetes increases the risk of all dementias [4] and so, most definitely, does cardiovascular disease and taking little or no exercise. The incidence of AD is greater in women than in men but there is encouraging evidence that this is not the case in women who have had Hormone – Replacement Therapy for at least 10 years.

We have all become weary and disheartened at being continually nagged to take more exercise because, apart from not smoking but this is probably the most effective thing we can do to extend and increase the length of our lives and our daily pleasure in them. We need aerobic exercise that benefits our hearts and lungs and so the blood and oxygen supply to our brains but it is surprising, and to me profoundly encouraging how very little exercise can make a difference. For example a useful study found that incidence of AD in a 3 year period was significantly less in elderly who walked 2.0 miles a day compared to 0.25 miles a day and even the lower mileage gave a slight but real advantage over total torpor. Another reassuring study [5] found that even gentle activities such as doing odd-jobs about the house, gardening and generally pottering about reduced the risk relative to that of deep inertia. It is mean to be a spoilsport about such a congenial result. I, for one, deeply wish to trust it but there is a small problem of participant selectivity: was pottering the cause or only a symptom of relative preservation in those who were chosen for assessment? Had those who could not even potter around a bit already crossed a frontier from which they could not return?

Academic colleagues are smug to learn that longer education lowers the risk of Alzheimer’s and other dementias. There is the usual problem of interpretation because longer education tends to buy a more comfortable life in non- toxic environments with better diet and more attention to health care and so lower risk of pathologies such as cardiovascular problems and diabetes that are risk factors for dementias of all kinds.

It is difficult, and perhaps even gauche to scrabble for a cheerful note on which to end a post on dementias. Studies of alcohol consumption probably provide the only glint of amusement we can wring out of this cheerless topic. A very large, and apparently well-conducted study in the Dordogne found that consumption of even 5 standard glasses of wine a day did not increase risks of dementia and that men and women drinking smaller amounts had slightly lower risks than tee-totalers. Convincing studies based in Copenhagen [6] and in Rotterdam [7], where wine production is not a significant part of the economy, found that modest daily consumption (1-2 glasses) of beer and spirits had no bad effects, and that drinking modest quantities of wine actually reduced risks. This inspires me to a new life plan: whenever anxiety that I may soon dement peaks to the point at which I must take action I shall avoid my nearest bottle-shops and manfully step out to the furthest that I can reach and buy as good a bottle of wine as I can afford. Beaujolaise if they have it.

Ebly, E. M., Parhad, I. M., Hogan, D. B., & Fung, T. S. (1994). Prevalence and types of dementia in the very old Results from the Canadian Study of Health and Aging.Neurology, 44(9), 1593-1593.